#include<bits/stdc++.h> using namespace std; const int N=50005; int n,a[N]; priority_queue<int,vector<int>,less<int> >q; int init() { scanf("%d",&n); if(n<=0) { return 0; } for(int i=0;i<n;i++) { scanf("%d",&a[i]); q.push(a[i]); } } int min() { int tmp; while(1) { tmp=q.top(); q.pop(); tmp=tmp*q.top()+1; q.pop(); if(q.empty())break; q.push(tmp); } return tmp; } int max() { sort(a,a+n); int anss=a[0]; for(int i=1;i<n;i++) { anss=anss*a[i]+1; } return anss; } int main() { while(1) { init(); int maxx=max(); int minn=min(); cout<<maxx-minn<<endl; } return 0; }